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MHT CET 2025 (25 Apr, Shift 2) · Matter Waves: de Broglie Wavelength

Matter Waves: de Broglie Wavelength question from MHT CET 2025 (25 Apr, Shift 2)

Q45MHT CET 2025 · 25 APR · SHIFT 2Difficult

Matter Waves: de Broglie Wavelength

An electron of mass ' mm ' and charge ' ee ' initially at rest gets accelerated by a constant electric field ' E '. The rate of change of de-Broglie wavelength of the electron at time ' tt ' is

(Ignore relativistic effect)( h=h = Planck's constant)

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Answer: (a)

  1. Constant force eEeE from rest: p=eEtp = eEt.
  2. λ=heEt⇒dλdt=−heEt2\lambda = \dfrac{h}{eEt} \Rightarrow \dfrac{d\lambda}{dt} = -\dfrac{h}{eEt^2}
  3. So the answer is (a).
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